The force required to stretch a spring is proportional to the distance it is stretched: F = kx where x is the stretch distance and k is a constant characteristic of the spring (big heavy springs have larger k values). Spring energy: Work has been done on a spring to compress or stretch it the spring has the ability to push or pull on another object and do work on it. It has the same units as work, the Joule (J). Use 1000 kg for the mass of the car.įirst we need the work done, which requires the force necessary to lift the car against gravity: Calculate the power delivered to the car. That is, the power is the work done divided by the time taken to do it.Įxample: A garage hoist steadily lifts a car up 2 meters in 15 seconds. When the work is done steadily (constant power), just use P = W/t. Work can be represented in a number of ways.įor the case where a body is moving in a steady direction, the work done by a constant force F It is a scalar-valued quantity with SI units of Joule. No work is done in either case.In physics, work is related to the amount of energy transferred in or from a system by a force. Holding the end of a rope on which a heavy object is being swung around at constant speed in a circle does not transfer energy to the object, because the force is toward the centre of the circle at a right angle to the displacement. Holding a heavy object stationary does not transfer energy to it, because there is no displacement. No work, as understood in this context, is done unless the object is displaced in some way and there is a component of the force along the path over which the object is moved. Work done on a body is accomplished not only by a displacement of the body as a whole from one place to another but also, for example, by compressing a gas, by rotating a shaft, and even by causing invisible motions of the particles within a body by an external magnetic force. If the force is being exerted at an angle θ to the displacement, the work done is W = fd cos θ. To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd. If the force is constant, work may be computed by multiplying the length of the path by the component of the force acting along the path. Work, in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force at least part of which is applied in the direction of the displacement. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century. 100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions. Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.
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